1. Field of the Invention
The present invention relates to an optical waveguide device manufacturing jig for manufacturing an optical waveguide device with high accuracy, a method of manufacturing the optical waveguide device by use of the jig, and the optical waveguide device. Particularly, it relates to a jig for manufacturing an optical waveguide device easily and accurately by guiding light at a predetermined wavelength into a container from predetermined positions preset in the jig in the condition that the container contains optical components inserted therein and is filled with a photo-curable resin solution; a method of manufacturing the optical waveguide device by use of the jig; and the optical waveguide device. The invention can be applied to manufacturing of an inexpensive low-loss apparatus such as an optical transmitter/receiver, an optical interconnection, an optical demultiplexer or an optical mutliplexer in the field of optical fiber communication.
2. Related Art
In recent years, attention has been paid to a technique in which beam-like light at a predetermined wavelength is guided into a photo-curable resin solution to thereby form an optical waveguide device on the basis of a self-focusing phenomenon. The self-focusing phenomenon is a phenomenon in which diverging irradiation light is confined in a solid phase region due to increase in refractive index in the solid phase when the liquid phase of the photo-curable resin is changed to the solid phase by light irradiation. The optical waveguide formed by use of this phenomenon is called a self-forming optical waveguide. Hereinafter, the self-forming optical waveguide is simply referred to as an optical waveguide. As a specific example, Japanese Patent Publication No. H08-320422 has disclosed a method of producing an optical waveguide system and an optical device using the optical waveguide system. This method is a method in which light having at least one predetermined wavelength is guided into a photo-curable resin solution through at least one place in the condition that optical components such as a light-receiving element, a lens, a prism, and a mirror are disposed in the photo-curable resin solution so that the optical components are coupled with one another by optical waveguides formed by use of the self-focusing phenomenon. In such a manner, there is formed an optical device containing various optical components connected to one another by optical waveguides. When, for example, various interference filters are erected along the optical axis, an optical waveguide type demultiplexing filter is formed. When, for example, a half mirror is disposed in the photo-curable resin solution and input and output ports of the optical device are coupled with each other by optical waveguides, an optical waveguide type branching unit or an optical waveguide type multiplexer is formed.
Particularly, in this example, the manufacturing method is configured so that light is guided into the photo-curable resin solution from two-way directions so that optical waveguides are coupled with each other by a so-called self-alignment effect in which the optical waveguides from two sides of the optical device are led into each other and coupled with each other at a midpoint to thereby reduce loss at the coupling portion.
In the related-art example, however, one kind of photo-curable resin solution is used. If the one kind of photo-curable resin solution is cured, it is difficult to form clads of optical waveguides. That is, there is a problem that transmission loss occurs because of slight damage or dust on surfaces of the optical waveguides. Moreover, in the related-art example, because the optical waveguides are only supported by the input and output ports or the optical components, there is another problem that an optical waveguide device strong against mechanical vibration cannot be produced.
In the related-art example, for example, a semiconductor laser as an optical component may be incorporated. That is, the wavelength used for forming the optical waveguides is made equal to the wavelength for actual applications (for example, in optical communication). In this case, there is a problem that the optical waveguides obtained on the basis of the relation between the predetermined wavelength and the absorption rate make transmission loss large.
Moreover, the feature of the related-art example is in that light is guided into the photo-curable resin solution from different directions to form optical waveguides from the different directions so that the optical waveguides are aligned at a midpoint by the self-alignment effect. Accordingly, the feature of the related-art example is to produce a low-loss optical waveguide device. It is, however, necessary to align the optical waveguides with accuracy, for example, of tens of micrometers at the midpoint in order to perform the self-alignment effect in the condition that the diameter of each of the optical waveguides is one hundred and several tens of microns. When optical components are disposed in the photo-curable resin solution, the positional or angular displacement of the optical components is a large factor which causes lowering of the self-alignment effect. In the related-art example, the optical waveguide devices are not always efficiently produced.